I would say Eight. The smallest increment of data on a computer is called a bit. A bit can hold only one of two values: 0 or 1, corresponding to the electrical values of off or on, respectively.
We rarely work with information one bit at a time. Bits are usually assembled into a group of eight to form a byte. A byte contains enough information to store a single ASCII character, like "h".
Therefore the byte, 8 bits, forms the most significant number in computing, the number EIGHT